We used to think obesity was caused by diet. And that’s certainly the #2 reason, but exercise is actually the #1 reason, recent studies show. Yes, they have now switched places for top-ranking cause.

One such study, “Lack of exercise, not diet, linked to rise in obesity, Stanford research shows” examined national health survey data from 1988 to 2010 and found significant increases in both obesity rates and sedentary behavior, while calorie consumption remained relatively unchanged. The researchers emphasize the dramatic decline in leisure-time physical activity and suggest that exercise and physical activity are important factors influencing obesity trends. The research highlights the correlation between obesity and sedentary lifestyles and calls for broader societal changes to promote healthy lifestyles and provide accessible exercise options.

Another study suggests that moderate-to-vigorous physical activity, adequate sleep duration, and limited screen time were associated with a lower likelihood of childhood obesity. Only about one-third of the study participants met the guidelines for physical activity and screen time, while just over half met the sleep guidelines. Meeting all three guidelines was associated with an 89% lower likelihood of obesity. The study highlights the importance of addressing multiple lifestyle factors in childhood obesity interventions. The researchers suggest that improvements in any of the guideline areas can significantly decrease the odds of childhood obesity. And since children have higher metabolisms, this would apply to older populations even more.

Another reason exercise is so important is its effect on appetite and the gut microbiome. Exercise is an appetite suppressant, thanks to certain hormone interactions.

Exercise also changes the balance of gut flora, independent of diet, which increases the metabolism and signals satiety (sense of fullness) more effectively, so people eat less.

Exercise also changes the types of cravings we have for food, as the body and brain are more inclined to want nutrient-dense foods to recover properly from exercise. Plus, on a subconscious level, the brain also doesn’t want to “ruin” the workout with crummy food, so choices change for the better.

So many reasons to exercise! And don’t wait either. Some people say, “I’ll lose some weight first and then go to the gym” but that rarely happens and if it does, you then start way later than you could have, losing tons of time to make the progress you want to make. It’s easier to lose weight when you start exercising first because then the diet part is easier to begin and establish as a habit.